Microbial isolates from infected pulps will be surveyed for the presence of enzymes which may contribute to the pathogenic process. This study will be conducted in three stages: (1) isolation of microbial isolates from infected pulps utilizing improved techniques for isolating obligate anaerobes, (2) testing for enzyme activity in these isolates (hemolysins, coagulase, gelatinase, casein hydrolysis, collagenase, hyaluronidase, chondroitinase, arylaminopeptidase, arylsulphatase, phosphatase), and (3) characterization of hyaluronidase and chondroitinase of endodontic streptococcal isolates.